Saavedra Jantuah joined last week’s strike of New York City fast food workers, the latest in a string of efforts to organize the new service economy’s low-wage workers. She knows she now has a long road ahead.

“Crispy chicken, fresh lettuce, three cheeses, ranch dressing wrapped up in a tasty, flour tortilla,” Mary J. Blige sings in a new Burger King commercial that premiered on Monday. But on Tuesday the ad disappeared.